Optical subassemblies (OSAs) are increasingly used in optoelectronic communication. For example, optoelectronic transceiver devices generally include a transmitter optical subassembly (TOSA) and a receiver optical subassembly (ROSA). Some OSAs that are integrated into optoelectronic devices include an optical receptacle that is configured to receive an optical fiber connector, such as an LC or an SC connector, such that the corresponding optical fiber is capable of optically and mechanically interfacing with an optical port of the OSA.
Optoelectronic devices also generally include one or more printed circuit boards having electronic circuitry. The electronic circuitry of a printed circuit board can create electromagnetic radiation (EMR). When EMR inadvertently escapes from an optoelectronic device, the EMR can cause electromagnetic interference (EMI) in nearby electronic devices which can degrade the functionality of those electronic devices. Therefore, it is important to control the inadvertent escape of EMR from optoelectronic devices.
Another related problem is the electromagnetic susceptibility (EMS) of optoelectronic devices. The EMS of an optoelectronic device is the degree to which the optoelectronic device is subject to malfunction or failure under the influence of electromagnetic radiation. Therefore, it is also important to control the inadvertent introduction of EMR into optoelectronic devices.
Controlling the escape/introduction of EMR from/into an optoelectronic device is generally accomplished by surrounding the optoelectronic device, as much as possible, with a housing formed from an electrically conductive material, which limits the escape/introduction of EMR, thus decreasing EMI in nearby electronic devices and in the optoelectronic device. It can be difficult, however, to control the transmission of EMR through required openings in the housing of an optoelectronic device, such as the optical ports that are configured to receive optical fibers.
As mentioned above, some OSAs that are integrated into optoelectronic devices include an optical receptacle with an optical port. Such OSAs are generally formed from a non-electrically conductive material, such as plastic, and is therefore not effective at limiting the transmission of EMR. EMR may, therefore, pass into the optoelectronic device by way of the port of the OSA and/or exit the optoelectronic device by way of the port of the OSA.
Attempts have been made to control the amount of EMR that passes through an OSA. One such attempt involved shielding a plastic OSA by coating the OSA with metal. This attempt proved problematic, however, due to the increased effort required to securely adhere metal to the plastic OSA, which resulted in the metal coating flaking off, thus decreasing the effectiveness of the shielding. This attempt also failed to address the lack of shielding where the OSA interfaces with an optical fiber.
Another attempt at controlling the amount of EMR that passes through an OSA involved forming the OSA from metal instead of plastic. This attempt also proved problematic because of the increased cost in manufacturing a metal OSA over a plastic OSA, and the increased cost of assembling a metal OSA together with a plastic receptacle and/or plastic lens(es). This attempt also failed to address the lack of shielding where the OSA interfaces with an optical fiber.
In light of the above discussion, a need currently exists for an OSA that is effective at limiting the transmission of EMR out of and/or into an optoelectronic device into which the OSA is integrated.